Electrical line system

ABSTRACT

An electrical line system has at least one magnetically compensated line system unit with at least two main conductors for transmitting electrical energy and further has at least one auxiliary conductor extending parallel to the at least two main conductors. The at least two main conductors and the at least one auxiliary conductor are phase-synchronized when the at least one auxiliary conductor carries current during operation of the electrical line system. The at least two main conductors and the at least one auxiliary conductor are arranged in a spatial arrangement relative to a first reference point in a first space extending parallel to the electrical line system, and the currents flowing in the at least two main conductors and the at least one auxiliary conductor are selected such that a vector sum of the magnetic field components emanating from the at least two main conductors and the at least one auxiliary conductor is substantially equal to zero at the first reference point. The spatial arrangement is defined by a distance between the at least two main conductors and the at least one auxiliary conductor relative to the first reference point and by a spatial distribution of the at least two main conductors and the at least one auxiliary conductor relative to the first reference point.

BACKGROUND OF THE INVENTION

The present invention concerns an electrical line system for thetransmission of low frequency electrical energy, with at least twoconductors. In this instance, low frequencies are understood to befrequencies used as standard for railway traction current supply (162/3Hz) and for general current supply (50 Hz or 60 Hz). However, theinvention is also significant for line systems transmitting directcurrent, such as is used for example in the application referred to asthe 700 kV network. This application can be seen as the boundary limitfor the definition of "low frequency". The effects of the magneticfields occurring as a consequence of such energy transmission systemscan in fact also be disruptive. The invention is also of interest forthose line systems in which for reasons of obtaining reduced transformerdimensions, for example, the operating frequency level is 40 kHz andabove.

As made clear by the numerous bibliographical references in the book"Elektrischer Strom als Umweltfaktor" by Konig/Folkerts, Pflaum-VerlagMunich, 1992, the presumption today is that above all magnetic, but alsoto a certain degree, electrical fields generated by current supply canin various circumstances have a negative effect on living organisms.

The main aspects under discussion in this case are cross-country linesin the high-voltage system and intermediate-high-voltage system anddomestic current supply, when these are configured as overhead lines.However, a comparable situation may arise in relation to magnetic andelectrical fields in the domestic environment too, despite the fact thatthe currents in this sphere which give rise to fields are usually ofconsiderably lower intensity. The reason why this situation may occur isthat in the domestic environment, the distances between people andcurrent-carrying lines are considerably shorter.

The task of the present invention is to counter these difficulties.

SUMMARY OF THE INVENTION

The electrical line system of the present invention is primarilycharacterized by:

at least one magnetically compensated line system unit comprising atleast two main conductors for transmitting electrical energy and furthercomprising at least one auxiliary conductor extending parallel to the atleast two main conductors;

the at least two main conductors and the at least one auxiliaryconductor being phase-synchronized when the at least one auxiliaryconductor carries current during operation of the electrical linesystem;

wherein the at least two main conductors and the at least one auxiliaryconductor are arranged in a spatial arrangement relative to a firstreference point in a first space extending parallel to the electricalline system, and wherein the currents flowing in the at least two mainconductors and the at least one auxiliary conductor are selected suchthat a vector sum of the magnetic field components emanating from the atleast two main conductors and the at least one auxiliary conductor issubstantially equal to zero at the first reference point; and

wherein the spatial arrangement is defined by a distance between the atleast two main conductors and the at least one auxiliary conductorrelative to the first reference point and by a spatial distribution ofthe at least two main conductors and the at least one auxiliaryconductor relative to the first reference point.

Preferably, at least one of the two main conductors is a split conductorthat is split into at least two single conductors and at least one ofthe remaining main conductors is an unsplit conductor. One of the singleconductors functions as the at least one auxiliary conductor. Thespatial arrangement of the at least two single conductors is determinedas a function of the currents flowing in the unsplit conductor and theat least two single conductors such that the magnetic field of theunsplit conductor is at least approximately compensated by the magneticfield of the single conductors in the first space extending parallel tothe electrical line system.

Advantageously, the currents in the single conductors are in phase andthe single conductors are positioned on opposite sides of the planedefined by a longitudinal extension of the at least one unsplit mainconductor and the first reference point.

The ends of the single conductors are expediently short-circuited to oneanother. Expediently, the single conductors have substantially identicalelectrical resistance and are positioned mirror-symmetrical to theplane.

In an alternative embodiment, the currents in the single conductors arein phase opposition and the single conductors are positioned on a sameside of the plane defined by a longitudinal extension of the at leastone unsplit main conductor and the first reference point.

The electrical line system preferably further comprises an electricalpower supply connected between the single conductors, wherein thecurrent of the power supply is phase-synchronized with the currenttransmitted with the electrical line system.

Preferably, at least one magnetically non-compensated line system unitis provided, wherein the at least one magnetically compensated linesystem unit and the at least one magnetically non-compensated linesystem unit extend substantially parallel to one another. The magneticfields of the at least one magnetically compensated line system unit andat least one magnetically non-compensated line system unit act on thefirst space extending parallel to the electrical line system. The atleast one magnetically compensated line system unit has a spatialarrangement such that at least partially a compensation of the magneticfields of the magnetically non-compensated line system unit is achieved.

The at least two main conductors for transmitting electrical energy andthe at least one auxiliary conductor are arranged in a stackedarrangement relative to the plane defined by a center line of the firstspace and a center line of the electrical line system or, in thealternative, are arranged adjacent to one another in the plane definedby a center line of the first space and a center line of the electricalline system.

Preferably, the at least two main conductors and the at least oneauxiliary conductor are arranged in a spatial arrangement relative tothe first reference point in the first space extending parallel to theelectrical line system and relative to a second reference point in asecond space parallel to the electrical line system and wherein thecurrents flowing in the at least two main conductors and the at leastone auxiliary conductor are selected such that a vector sum of themagnetic field components emanating from the at least two mainconductors and the at least one auxiliary conductor is substantiallyequal to zero at the first and second references points.

The single conductors are arranged about the unsplit conductor so as tobe substantially positioned on a circle.

The at least one magnetically compensated line system unit is a cablewith insulation cover.

The cable carries single-phase current and comprises one of the splitconductors and one of the unsplit conductors, wherein the singleconductors and the unsplit conductor are each individually insulated andwherein the single conductors symmetrically surround the unsplitconductor.

Preferably, the electrical line system further comprises a neutralconductor, wherein the single conductors are arranged about the neutralconductor so as to be substantially positioned on a circle.Advantageously, a neutral conductor split into single neutral conductorsis also provided, wherein the single neutral conductors surround thesingle conductors of the main conductors so as to be substantiallypositioned on a circle in order to shield against the formation of anexternal electrical field. A ground conductor arranged centrally withrespect to the single conductors of the main conductors and the singleneutral conductors may also be provided.

Alternatively, a ground conductor split into single ground conductorsmay be provided, wherein the single ground conductors surround thesingle conductors of the main conductors in order to shield against theformation of an external electrical field.

The cable may be designed to carry polyphase current and in thisembodiment comprises one of the split conductors for each phase of thepolyphase current, wherein each one of the single conductors isinsulated, and wherein all of the single conductors are substantiallypositioned on a circle. Expediently, a neutral conductor is provided,wherein the single conductors are arranged about the neutral conductorso as to be substantially positioned on a circle. The neutral conductormay be split into single neutral conductors, and in this embodiment thesingle neutral conductors preferably surround the single conductors soas to be substantially positioned on a circle in order to shield againstthe formation of an external electrical field.

A ground conductor may be arranged centrally with respect to the singleconductors and the single neutral conductors. In an alternativeembodiment, the ground conductor is split into single ground conductors,wherein the single ground conductors surround the single conductors inorder to shield against the formation of an external electrical field.

Advantageously, the cable has free ends and each one of the free endscomprises a connection device in the form of a plug. An electricalconnection of the single conductors of each one of the split conductorsis provided in each one of the connection devices. The electrical linesystem may further comprise a counter member for each one of theconnection devices, and the counter members and the connection devicesare embodied such that the connection device can be inserted into thecounter member only in one position in which a neutral conductor of theconnection device contacts a neutral conductor of the counter member.

In yet another embodiment of the present invention, the cable isconfigured as a twin lead and the single conductors are slightly offsetrelative to a plane defined by the twin lead in which plane the unsplitconductor is positioned.

When the cable carries polyphase current, the single conductors arepreferably arranged in two planes that are essentially parallel to oneanother.

In another embodiment of the invention, the at least one magneticallycompensated line system unit is an earth cable unit for transmittinghigh voltage current and the single conductors are in the form ofseparated conductors.

The at least one magnetically compensated line system unit is a railwaytraction current system having a railway traction current line wherein afirst one of the main conductors is selected from the group consistingof an overhead contact line and a lateral contact line and wherein asecond one of the main conductors is in the form of a track. One of thefirst and second main conductors functions as the split conductor. Thesplit conductor is formed by providing a separate conductor in additionto the respective main conductors.

In a preferred embodiment of the invention, the track functions as thesplit conductor and is comprised of two of the single conductors, with afirst one of the single conductors being the railway track proper andwith a second one of the single conductors being a separate conductor,wherein the separate conductor is arranged such as a function of thecurrent flowing therethrough that a compensation of the magnetic fieldcomponents takes place in the first space. Preferably, the separateconductor extends underground and parallel to the track. Advantageously,a transformer for supplying a compensation current is provided and thesingle conductors of the split conductor each have a first and a secondend and are connected to one another with the first ends, wherein thetransformer is connected to the second ends.

In an other embodiment, a plurality of transformers for supplying acompensation current is provided, wherein each one of the transformersis connected between ends of two of the single conductors of the splitconductor.

The separate conductor is divided into short conductor sections and theelectrical line system further comprises a sensor device, wherein thesensor device determines in which one of the short conductor sectionscurrent is flowing, and switching elements positioned betweenneighboring ones of the short conductor sections. The switching elementssupply compensation current only to those ones of the short conductorsections corresponding to portions of the first and second mainconductors carrying current.

The sensor device is preferably a magnetic field sensor.

In yet another embodiment of the present invention, a plurality of theseparate conductors are provided substantially in parallel to therailway traction current line.

Preferably, the single conductor has a cross-sectional area that issmaller than a cross-sectional area of the unsplit conductor.Advantageously, the sum of the cross-sectional areas of the singleconductors is substantially identical to the cross-sectional area of theunsplit conductor.

The single conductors of each one of the split conductors expedientlyhave the same identification markings, preferably in the form of a colorcode.

In accordance with the present invention, an electrical line system(primary system) is configured with at least two conductors for thetransmission of electrical energy, in such a manner that a minimum ofone additional line system (secondary system) is provided which runs atleast approximately in parallel to the conductors of the (primary)system, that a power supply is provided for this line system with acurrent which is phase-synchronized in relation to the current in theoriginal line system, and that the spatial arrangement of at least thisone additional line system and the current flowing as a result of thepower supply are selected so that magnetic fields caused by the currentsin the individual conductors of the line systems compensate one anotherto an almost complete degree in an area of space running approximatelyin parallel to the line systems and which at least approaches a magneticfield-free condition.

In this arrangement, the configuration can be such that the line systemsshare one conductor in such a way that a conductor which is split intoat least two single conductors, and an unsplit conductor are provided,and that geometrical position of the single conductors is arrangeddependent on the currents flowing in the conductors, in such a way thatthe magnetic field of the current caused by the transmitted energy inthe unsplit conductor is at least approximately compensated by themagnetic fields of the currents in the single conductors in the area ofspace running approximately in parallel to the line system. Splitting ofa conductor can also be effected in more than two single conductors.This makes additional freedom possible in the geometrical arrangement ofthe entire line, which can represent an advantage in individual cases.

If the currents in the single conductors are in in-phase condition, itis advisable to locate these on opposite sides of the surface defined bythe longitudinal extension of the unsplit conductor and a point lying inthe compensation zone. It is also advantageous if this arrangement alsomeans the ends of the single conductors of the individual splitconductor are short-circuited to one another.

Furthermore, it is also beneficial if the single conductors possess atleast practically the same electrical resistance and are located atsymmetrical angles to the surface defined by the longitudinal extensionof the unsplit conductor and a point lying in the compensation zone.

If the currents in the single conductors are in phase opposition, it isadvisable to locate these on one side of the surface defined by thelongitudinal extension of the unsplit conductor and a point lying in thecompensation zone.

An embodiment in which a current source is connected between singleconductors of the split conductor and the current source isphase-synchronized with the electrical energy transmitted in the linesystem can also be advantageous. It would be suitable for the currentsource to operate with impressed current, in other words with a highlevel of internal resistance in comparison to the circuit formed by thesingle conductors.

In the case of several (primary) line systems which run at leastapproximately in parallel and which have an effect on the area of space,it is advisable for a configuration to be provided which compensates themagnetic fields in only a part of these line systems, and for linesystems configured to provide this compensation, to provide a mechanismfor the spatial displacement of the conductors which enables at leastpartial compensation also to be effected in the case of magnetic fieldsof the other (primary) line systems.

In certain cases, it is beneficial if the single conductor or singleconductors of the individual split conductors are located in at leastpractically symmetrical circles, or in a preferred embodiment in fullysymmetrical circles, around the unsplit conductor. This arrangement isof most interest in the case of configuration as a single phase cablewith insulating cover. In such a situation, it is advantageous toconfigure one of the two conductors provided for current transmission asa split conductor with its single conductors individually insulated inthe same manner as the unsplit conductor, and to arrange the singleconductors of the split conductor so they symmetrically enclose theunsplit conductor between them.

The cable ends can be provided with connection devices of prior art. Theelectrical connection of the single conductors of each of the splitconductors is provided in the connection device on each cable end. Inone example, the connection device can take the form of the terminalconnector strip of a piece of electrical equipment. The connectiondevice can be a plug on at least one of the ends of the cable. If thecable is equipped with a plug on one end and an in-series adapter on theother, the cable can be used as a device of prior art referred to as anextension cable. This is particularly advantageous, for example, in asituation such as when the current line running inside a bedroom wall toprovide illumination at the bedside cabinet is located in the area ofthe bedhead. The bedside lighting connection can then be brought from acurrent socket through such an extension cable which is not routedthrough the bedhead area. Thus, to a considerable extent, the extensioncable removes magnetic fields from the bedhead area, and in acorresponding configuration in accordance with a further development ofthe invention, can rid areas of electrical fields. In such anarrangement, it is advantageous if each individual plug and its matingpart are configured in accordance with prior art in such a manner thatthe plug can only be inserted into its mating part if it is positionedso that the neutral conductor connection of the plug is in contact withthe neutral conductor bushing of the mating part. This ensures that notonly the magnetic fields, but also the electrical fields can be reducedto a negligible amount in the area of space in which compensation is tobe effected in the required manner.

In the case of a cable for polyphase current with insulating cover, itis beneficial if each of the conductors assigned to one current phase isconfigured as a split conductor with its individual insulated singleconductors, and if the single conductors of the split conductor arelocated in at least practically symmetrical circles, and in the case ofan additional neutral conductor (zero conductor) being provided, if theyare located, in a preferred embodiment, in symmetrical circles aroundthe neutral conductor.

Furthermore, it is advantageous if the neutral conductor is alsoconfigured as a split conductor, and if its single conductors surroundthe circular arrangement of single conductors in the conductors whichare each allocated to one current phase, in such a manner as to providescreening against the formation of an external electrical field.

The ground conductor can also be configured as a split conductor, andits single conductors can surround the other conductors in the cable insuch a manner as to provide screening against the formation of anexternal electrical field.

The invention can also be beneficially used in a cable which isconfigured as a twin lead. In this arrangement, it is advantageous ifthe single conductors are located on two planes which are at leastapproximately in parallel to each other, and in the case of a polyphasesystem, if all conductors are split into single conductors. Thesedifferent versions can also be used in the current supply lines ofcurrent paths and in current paths in consumers which possess amulti-planar layout with at least a degree of similarity from plane toplane.

In the case of the line system being configured as an earth cablesuitable for transmitting high-voltages, it is advantageous to providethe single conductors as separated conductors.

The invention is also particularly important in the case of railwaytraction current systems. In such systems of prior art, the trackfunctions as one conductor and an overhead contact line (German FederalRailways) or a lateral contact line (German "U-Bahn" or undergroundrailway systems) is used as the other conductor of a two conductorsystem which usually operates with an operating voltage of 15 kilovoltand operating currents of 100 Amps and more. In accordance with thepresent invention, one of the two conductors mentioned above issupplemented to make a split conductor. It is advantageous if the trackis supplemented by at least one single conductor to make the splitconductor, and if the spatial arrangement of the single conductor isselected in relation to current flowing through it, in such a mannerthat compensation is effected in the area of space referred to.

In one embodiment, the single conductors are connected together at oneof their ends, and the other ends of the single conductors are connectedto a transformer which supplies the compensation current.

In a further embodiment, a transformer which supplies the compensationcurrent is connected at each end of the single conductors between singleconductors. In a railway traction current system configured inaccordance with the present invention, it is advantageous if the singleconductor which supplements the one conductor to make it a splitconductor is divided into short single conductor sections and if asensor device is provided which determines which line section formed byan overhead contact line or a lateral contact line and track has currentflowing in it. Switching equipment shall be provided at the transitionpoints from one single conductor section to the next, such that theswitching equipment only supplies compensation current to those singleconductor sections in which current is flowing in the overhead or thelateral contact line. In this manner, due account can be taken of thesituation that compensation is only effected for the magnetic fieldwhich projects outwards in those railway traction current sections whichlie between the incoming feeder point in the railway traction currentcircuit and the railway traction current section in which an electriclocomotive is located, and no other railway traction current linesections can be loaded by a magnetic field as a result of thecompensation field. In order to determine the condition referred to, itis advantageous if a magnetic field sensor is provided as the sensordevice, for example a coil which corresponds to the railway alternatingcurrent frequency of 162/3 Hertz. In the case of direct currentoperation, a Hall probe, for example, can be used in accordance withprior art, which modifies its electrical resistance value in thepresence of a d.c. magnetic field and the resistance modification can beemployed as a switching criterion.

It is also worthy of mention that more than one single conductor can beprovided and be routed at least approximately in parallel to the railwaytraction current line. As in the other cases, several single conductorscan be provided.

In many practical applications for the present invention, it is aconsiderable advantage if, in a preferred embodiment, thecross-sectional area of the single conductors can in each case beconsiderably smaller in comparison to the unsplit conductors, inparticular in such a manner that the total cross-sectional area of thesingle conductors at least approaches the cross-sectional area of theunsplit conductor. On the one hand, this means that neither the size ofthe conductor material nor the cable cross-section are increasedunnecessarily, whilst on the other hand, progress is made towardsachieving the degree of flexibility required in particular for cableswith regard to their bending properties

In order to guarantee the correct allocation of single conductors toconnections which continue the circuit, such as a connection device, itis advantageous if the single conductors, each of which forms a splitconductor, are provided with the same marking, in particular as concernsthe coloring of their insulation. Even a differentiation method whichrelies on shape, such as the differentiated corrugation of loudspeakerconnection cables used in stereo systems, can be used to beneficialeffect.

BRIEF DESCRIPTION OF THE DRAWINGS

In the text below, the present invention is explained in greater detailwith the help of sample configurations illustrated in the drawings.

In the drawings,

FIG. 1 shows the spatial representation of a line system, which is usedto explain in more detail the method by which the present inventionoperates,

FIG. 2 shows a vector diagram of the system in accordance with FIG. 1,

FIG. 3 shows a sectional view of a single phase high voltage system forrailway traction current supply with, for example, 115 kV,

FIG. 4 shows a three-phase current system as employed as standard in the115 kV range and above, however reconfigured in accordance with thepresent invention,

FIG. 5 shows a circuit diagram for the configuration of the transformerdevice in order to guarantee current splitting for the individualconductors,

FIG. 6 shows a fully symmetrical single phase system in accordance withthe present invention,

FIG. 7 shows the vector diagram of the magnetic field for a system inaccordance with FIG. 4,

FIG. 8 shows two single phase, fully symmetrical systems in accordancewith the present invention,

FIG. 9 shows the vector diagram of the magnetic field in a system inaccordance with FIG. 8,

FIG. 10 shows a view in accordance with FIG. 3, however with anadditional feature for effecting compensation for the electrical field,

FIG. 11 shows a sectional view of a cable for transmitting three-phasecurrent in a star connection, e.g. with a neutral conductor, howeverwithout a ground conductor (also referred to as PE in standardizedtechnical terminology),

FIG. 12 shows a cable in accordance with FIG. 11, however with a PE,

FIG. 13 shows a single phase cable, as could be used for example as anextension cable in a low-voltage system (230 V),

FIG. 14 shows a single phase cable, for example in accordance with FIG.11, however with compensation of the magnetic field resulting fromtwisting the single conductors of cables as normally performed forreasons of flexibility,

FIG. 15 shows a cable in accordance with FIG. 14, however with PE,

FIG. 16 shows a cable for transmitting three-phase current in threephases in a delta circuit with contradirectional twisting of the singleconductors to give additional magnetic field compensation,

FIG. 17 shows a cable for transmitting three-phase current in threephases in a star connection, e.g. with a neutral conductor, and with aPE and special twisting to give additional magnetic field compensation,

FIG. 18 shows an arrangement referred to as a twin lead, howeverconfigured in accordance with the present invention with single phasecurrent supply and two PE conductors,

FIG. 19 shows a twin lead for transmitting three phase current in threephases with a neutral conductor and PE,

FIG. 20 shows a modified twin lead in accordance with FIG. 17,

FIG. 21 shows a twin lead similar to the twin leads in accordance withFIG. 18, however with particularly thorough magnetic field compensation,

FIG. 22 shows a diagram which makes clear the effect of an embodimentconfigured as in FIG. 3 in accordance with the present invention,

FIG. 23 shows a railway traction current system with an overhead contactline and the track as conductor of the primary line system and a singleconductor located above ground,

FIG. 24 shows a railway traction current system with an overhead contactline and the track as conductor of the primary line system in accordancewith FIG. 23 and a single conductor located underground,

FIG. 25 shows a railway traction current system in accordance with FIG.23, in which the additional single conductor is divided into sectionswhich are connected by switching equipment,

FIG. 26 shows the connection of a cable and its single conductors to thescrew-type terminals of a standard safety plug,

FIG. 27 shows an advantageous configuration of the plug in accordancewith FIG. 26 which simplifies clamping of the single conductors,

FIG. 28 shows a male connector and female connector configuration whichensures that the connection can only be effected in a pre-specifiedposition,

FIG. 29 shows two components which enable a standard safetyplug-and-socket connection to be modified in accordance with theconnection in FIG. 28,

FIG. 30 shows a further development in respect to the arrangement of theconductors,

FIG. 31 shows an explanation of the further development in accordancewith FIG. 30 for a single phase system,

FIG. 32 shows an explanation of the further development in accordancewith FIG. 30 for a three-phase current system,

FIG. 33 shows a combination of various types of arrangements for athree-phase current system and

FIG. 34 shows a sample layout for effecting compensation in severalareas of space.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a cross-sectional view through a line system, by means ofwhich the compensation is explained in greater detail.

Conductors L1 and L2 represent the outward or return conductor of asingle phase two-wire line for transmitting electrical energy of 11.5 kWat a frequency of 50 Hertz and voltage of 230 Volt. This means that eachof the two conductors carries a current of approximately 50 Amps. Thedistance between the two conductors is approximately 0.5 m. Such asituation arises for example in the current supply to a house through anarrangement referred to as a service entry mast line. This gives rise totwo magnetic field components H1 and H2 at a distant reference point P,whereby these components are caused by the current in the outward andreturn conductor. Both the magnetic field components are in phaseopposition, but are not in the same alignment due to the distancebetween the conductors. Their sum is dependent on the distances (a1, a2)between the reference point P and each conductor (L1 or L2) in thecross-sectional plane Q. A sum component Hs is created in accordancewith prior art, and Hs is not equal to zero.

If an additional two-wire system with conductors L3 and L4 is added, asshown in FIG. 1, and if a current which is phase-synchronized to linesystem L1, L2 is allowed to flow, additional magnetic field componentsH3 and H4 are created, with the alignment of these magnetic fieldcomponents being dependent on the position of conductors L3, L4 in thecross-sectional plane and the magnitude of the magnetic field componentsbeing dependent on the current flowing within them as well as on therespective distances a3, a4 from point P. If the phase selection iscorrect (in example H2 and H4 and H3 and H1, each in phase opposition),a vector diagram in accordance with FIG. 2 will result.

Phase-synchronized condition is understood to mean that the currents inthe conductors under consideration are not only of the same frequencyand have the same amplitude sequence over time, but are alsophase-locked in relation to each other, and depending on theapplication, are in phase or in phase opposition.

The sum components of the four magnetic field components H1, H2, H3 andH4 in the reference point P can be reduced to zero by displacing L3, L4and selecting the current IK in L3, L4.

In practical cases, conductor L2 can be combined with conductor L4 tomake one conductor.

The current in the second line system can be generated in various ways.One method is to split the original L2 conductor into two conductors andshort-circuiting the two single conductors to the ends of the linesystem. The current in each of the single conductors is then practicallydetermined by the relationship between the resistances of the two singleconductors, whereby the relationship can preferably be realized by usinglines of differing cross-sections.

Another method is to connect a current source either in the additionalline system or, in the case referred to above where the conductor issplit into two, to connect a current source between the two singleconductors, whereby the current source, in a preferable embodiment,operates using impressed current and is phase-synchronized to thecurrent flowing in the original line system. If the phase of the currentflowing through this current source in conductor L2 is in phaseopposition to the current which was originally flowing in L2, thecurrent flowing in L2 is reduced to a level lower than the originalcurrent. Furthermore, this has a side effect that the line transmissionlosses in L2 for the primary line system are reduced. However, ifin-phase condition prevails, the current in L2 is increased in relationto the original current.

The electrical energy required for magnetic field compensation in a linesystem in accordance with the present invention is negligible incomparison to the energy which is to be transmitted in the primary linesystem (L1, L2), because the source voltage which has to be applied isvery small in comparison to the operating voltage between conductors L1and L2.

FIG. 3 shows a high-voltage line configured as a two-wire system withconductors L1, L2 in accordance with the present invention. In thiscase, conductor L2 is split into conductors L21 and L22. The routing ofconductor L1 and a compensation point PK defined near the conductorroute or a parallel to conductor L1 running through compensation pointPK define a reference plane extending along the route which is specifiedin the cross-sectional view in accordance with FIG. 3 by a line ofsymmetry SL which touches points L1 and PK. The two conductors L21 andL22 resulting from the splitting of conductor L2 are located atsymmetrical angles to the line of symmetry SL and far enough away fromthe compensation point PK that the vector sum H2S of both individualmagnetic fields H21 and H22 in the compensation point PK has the valueof the magnetic field vector H1 which is to be allocated to conductor L1in the compensation point. In the example in FIG. 3, both individualmagnetic fields H21 and H22 are located in fully symmetrical positionsto the line of symmetry SL. If conductors L21 and L22 are carrying halfthe current of conductor L2 each, the amounts of the appropriatemagnetic fields H21 and H22 are also the same, due to the distance d ofconductors L21 and L22 from the compensation point PK also being thesame. Conductors L21 and L22 are located at symmetrical angles to theline of symmetry SL, and so the combined vector H2S of magnetic fieldsH21 and H22 is a magnetic field vector H2S which has a directional axisof orientation identical to that of magnetic field vector H1. Outwardand return currents in the single phase system give rise to magneticfields H1 and H2 with opposite orientation in the compensation point PK(phase opposition). This means the magnetic fields compensate each othercompletely in the compensation point PK.

FIG. 4 shows a possible method of compensating the magnetic fieldgenerated in a three-phase system with conductors DL1, DL2 and DL3. Thefigure shows a cross-sectional view, and as in FIG. 3, the straight linethrough points DL1 and DPK represents the reference parameter for anarrangement of conductors with symmetrical angles. In this case, thesingle conductors DL21 and DL22 resulting from splitting conductor DL2are in a fully symmetrical arrangement, similarly to the arrangement inFIG. 3. When at a corresponding distance from the compensation point DPKand with the corresponding phase, the combined vector DH2 to beallocated to these conductors has the same value as DH1 and also thesame directional axis orientation as DH1. The conductor DI2 is assumedto be of identical size in both of the single conductors DL21 and DL22.Conductor DL3 is split into single conductors DL31 and DL32. Thedistances Dd31 and Dd32 between these two single conductors and thecompensation point DPK and the currents DI31 and DI32 flowing in themare assumed to be of differing values. Currents DI31 and D132 are ofsufficient magnitude that their corresponding magnetic field vectorsDH31 and DH32 in the compensation point DPK are of the same amount whenthey have comparable phases, and their combined vector DH3 correspondsin value with that of DH1. As far as momentary observation is concerned,for example with maximum electrical conductor amplitude and fullysymmetrical three-phase current operation, the values of the threemagnetic fields DH1, DH2 and DH3 are identical. The entire arrangementis in angular symmetry, and so all three magnetic field vectors DH1, DH2and DH3 share the same orientation, namely the orientation of DH1. It isa known fact that the sum of currents DI1, DI2 and DI3 in a three-phaseconductor system is equal to zero at any time, and therefore this isalso true for the sum of the individual magnetic field vectors incompensation point DPK. In the example shown in FIG. 4, the vectorsindicated apply for that moment when DI1=-DI2/2 and DI1-DI3/2. Becausethe conductors determine the magnetic fields, this can be applied in thesame way for the corresponding magnetic fields.

It is to be taken as adequately self-evident that when a conductor issplit into several current-carrying single conductors of identicalproportions, the single conductor currents will be divided equallybecause the single conductors connected in parallel all have the sameresistance value. FIG. 5 shows a circuit which presents one option fortargeted external current distribution. The relationships between thetransformation ratios of the four transformers 31, 32, 33 and 34 can beused for setting the distribution of conductor I between two singleconductors 35 and 36. In the example, the distribution is effected insuch a manner that half the current I flows in each conductor 35, 36 asflows in conductor 37 which is not split. In other words, thedistribution is dependent on the supply voltage of each of the twosingle conductors.

The arrangement shown in FIG. 3 only provides magnetic fieldcompensation which is effective on one side in relation to the route ofthe high voltage line, however compensation can be effected on bothsides. FIG. 6 shows a configuration for this which enables acompensation effective symmetrically to the route with a single phasesystem. A conductor 401 is located on the axis of symmetry 402 of theroute, the second conductor is split into four single conductors 403,404, 405 and 406 which are located symmetrically to and at the samedistance 407 to the axis of symmetry 402. The two compensation points408 and 409 are located at asymmetrical points on opposite sides of theroute, and two axes of symmetry 410 and 411 proceeding from thesecompensation points 408 and 409 intersect at point 412 on the axis ofsymmetry 402. The four single conductors 403, 404, 405 and 406 and thecompensation points 408 and 408 together form two pairs of straightlines 414, 415 and 416, 417, all of which form the same angle 413 toboth the axes of symmetry 410 and 411. In the diagram, the surface ofthe ground is represented by 420. In order to achieve optimum magneticfield compensation symmetrically to the route in compensation points 408and 409 with the single conductors arranged in this way, the unsplitconductor 401 has to be located slightly below the point of symmetry412, and the currents in the four single conductors 403, 404, 405 and406 taken as pairs 403, 405 and 404, 406 must be the same amount. Thedistribution of the total current which corresponds to the current in401 is different in both single conductor pairs 403/405 and 404/406. Inthe example, this is 2:1. The split required is dependent on how far theunsplit conductor is located below the point of symmetry 412, and on howthe other geometrical relationships are set. As in the case of the otherconfiguration examples, the split can be determined using the vectordiagram.

The sample arrangement shown in FIG. 6 results in a picture of themagnetic field vectors across the surface of the earth 420 for thecompensation point 408, as is shown for a specific conductor currentstrength in a single phase system in accordance with FIG. 7. Theconductor 401 which carries the entire current generates a magneticfield described by the vector 501 which gives its amount (length) andorientation in space (shown in phase opposition in the example), wherebythe magnetic field depends on the strength of the current in conductor410, its distance 419 from the compensation point 409 and itsorientation in space(at right angles to 419). The magnetic field vectors502 and 503 corresponding to conductors 403 and 405 are determinedaccordingly. If these vectors are added together, they produce thecombined vector 504. In the case of conductors 404 and 406, the vectorsare 505 and 506 or the combined vector 507. Vectors 504 and 507 areallocated to the single conductors 403, 404, 405 and 406; they aretherefore in in-phase condition. The sum of their vectors represents thetotal magnetic field vector 501 of the entire current in the singleconductors. In the phase conditions reduced to their fundamentals in theillustration, this magnetic field vector is practically of the samemagnitude as the magnetic field vector of the current in conductor 401which is in phase opposition. The directional axes are the same, and soboth magnetic fields compensate one another. The exact values aredependent on the overall geometrical relationships and can be derivedfrom the vector diagram as explained above.

FIG. 8 shows one example of a magnetic field compensation arrangementwhich is fully symmetrical to the route, in the case of two two-phasesystems 601, 602, 603 and 604, 605, 606 which each have one conductorsplit into two parts 602, 603 and 605, 606 above the surface of theearth 624. In this example, conductors 602/605, 601/604, 603/606 of theentire system are in pairs and located symmetrically to the main axis ofsymmetry 607. Straight lines through the two compensation points 608,609 and the conductors 602, 601, 603 and 605, 604, 606 form two equalpairs of angles 622, 623 on each side.

The intersections of the straight lines 610 to 620 determined by thepairs of angles 622, 623 coincide with the position of the conductors.610 and 617 intersect at 602. 611 and 616 intersect at 605. 612 and 619intersect at 601. 613 and 618 intersect at 604. 614 and 621 intersect at603. 615 and 620 intersect at 606.

The example in FIG. 9 shows the magnetic field vector situation forcompensation point 608, and correspondingly for compensation point 609as well, which results from a fully symmetrical arrangement ofconductors. Vectors 701 and 702 and their combined vector 703 belong tothe two unsplit conductor currents 601, 604 (the three vectors areentered in FIG. 9 in phase opposition). Vectors 704 and 705 and theircombined vector 706 belong to the split conductor currents 602 and 605and vectors 707 and 708 and their combined vector 709 belong to thesplit conductor currents 603 and 606. These vectors produce the overallmagnetic field vector 703 for the total current which, in the splitconductors 602, 603, 605, 606 and as reverse current, is identical withthe current in the unsplit conductors 601, 604. Both total currentstherefore have the same amounts and the same directional axes in thecompensation point 608. The situation is fully compensated because boththe currents or magnetic fields are in phase opposition.

FIG. 10 illustrates the possibility of additionally compensating theelectrical field whist compensating the magnetic field. An additionalelectrical conductor E is used here as a supplement to the magneticfield compensation at point PK for a two-phase current system L1, L2with split conductors L21 and L2 illustrated in FIG. 3, whereby theadditional electrical conductor has an identical voltage potential tothat of conductor L1, but does not conduct any current. This means themagnetic field compensation is not disturbed by this measure. FIG. 10therefore simply includes the vectors which describe the electricalfield. The graphical orientation of these vectors is effected inaccordance with the familiar procedure of mirroring the conductors withpotential to earth against the surface of the earth 801. This results inthe mirror points L1', L21', L22' and E' which are in each case to beassigned phase opposition. The individual vectors of the electricalfield are determined by the level of the potential, the distance betweenthe conductors and the compensation point PK and the directionalorientation described by the straight line connections betweenconductors L1, L21, L22, E, L1', L21', L22', E' and the compensationpoint PK.

Conductor L1 creates an electrical field described by the vector 802which can be derived from the vector sum of the vectors 803 and 804(phase opposition) which are determined by conductors L1 and L1'. Inaccordance with this, the vector 805 is allocated to conductor L21whereby vector 805 is defined by the sum of vectors 806 (L21) and 807(L22'), and in the same way, vector 808 is allocated to conductor L22and vector 808 is made up of vectors 809 (L22) and 810 (L22'). The sumof vectors 805 (L21) and 808 (L22) gives a vector 811 (L21 and L22)which already goes some way towards compensating vector 802 (L1). Theremaining electrical field is described by vector 812. The inclusion ofthe non-current carrying conductor E, whose potential corresponds tothat of conductor L1, results in a vector for the electrical fieldswhich approximately corresponds to vector 802 which is dependent on L1.Given an opposite direction of orientation, the resulting vector sum 813corresponds to the value of vector 811, and this gives a very goodcompensation of the electrical field at the compensation point PK. Inthis example, a further development of the present invention can haveconductor E included in the current load of conductor L1 in order, forinstance, to reduce any ohmic losses.

The cross-sectional view illustrated in FIG. 11 shows an electrical linesystem in accordance with the present invention as cables fortransmitting electrical energy in multiple phases. In a three-phasecurrent system, the three phase conductors 91, 92, 93 are for exampleeach divided into three single conductors 911, 912, 913; 921, 922, 923;931, 932, 933 which are arranged in alternating symmetrical circlesaround the central neutral conductor 9N. In this arrangement, theweakness and the regularity of prevention of the disruptive magneticfield outside the cable is in direct proportion to the number of splitconductors included in the arrangement.

The line system transmits the entire outward and return current, andtherefore the sum of all the currents is zero. All currents which areflowing are broadly distributed in symmetrical circles as far as theircross-section is concerned because of the split phase conductors andbecause of the centrally arranged neutral conductor, and so the magneticfield is optimally compensated outside the cable. It is advisable todimension the total cross-sectional area of the single conductors of asplit conductor in accordance with the size required by the wholeunsplit conductor.

The electrical line system arranged in accordance with the presentinvention, as illustrated for example in FIG. 11, can also be used toprevent electrical fields arising outside the cable in accordance withthe cross-sectional arrangement shown in FIG. 12. The three phaseconductors for a three-phase current system 101, 102, 103 are each splitinto two single conductors 1011, 1012: 1021, 1022; 1031, 1032 and aredistributed in an arrangement of even symmetrical circles (circle 105).The eight split single conductors 10N1 to 10N8 of neutral conductor 10Nare located on a correspondingly larger circle 106. If a groundconductor 10PE is used, it is located centrally.

The cross-sectional drawing in FIG. 13 shows a further embodiment of anelectrical line system as a cable, in accordance with the presentinvention. In a two conductor system with both conductors 111 and 112,conductor 112 is split into eight single conductors 1121 to 1128 whichare arranged in a symmetrical circle (circle 114) around conductor 111which is located in the center. The large number of single conductors1121 to 1128 means that practically no fields are generated outside thecable. This therefore guarantees good magnetic field compensation nomatter what the polarity of, for example, a plug inserted in a sockethappens to be. In order to prevent an electrical field extending beyondthe cable, it is sensible to have the ground conductor 11PE which issplit into four single conductors 11PE1 to 11PE4 as the outermost layerof the loop (circle 115) and use it as a shielding mechanism at the sametime.

To give optimum compensation of the magnetic field existing outside acable, it is necessary that the opposing fields generated by the outwardand return currents should be of the same magnitude and should have thesame phase conditions and be distributed as evenly as possible at everypoint in the surrounding space, as is guaranteed if the outward andreturn currents are identical. It is also necessary for the spatialorientation of the mutually compensating fields to be in concordance ifthe compensation is to be practically total. This situation is onlyguaranteed if all current-carrying conductors are routed in parallel. Ifthis should not be possible due to technical reasons associated with themanufacture of cables, for example due to different conductor twisting,this can be achieved in accordance with the present invention with splitconductors in which due to contradirectional twisting of the splitconductors the resulting vector of the magnetic field as assigned toeach current path adopts a ninety degree alignment to the axis of thecable, thus fulfilling the requirement that the field vectors should beof the same value. In accordance with the present invention, in order toobtain a distribution of current in symmetrical circles which is asevenly spread as possible over the cross-section of the cable, it isadvisable to twist the split conductors contradirectionally in pairs.

FIG. 14 shows a cable for two current paths (outward and return current)in which one conductor 121 split into two insulated single conductors122, 123 is fitted centrally, surrounded by two conductors. Conductor122 has a right-hand twist, and accordingly, conductor 123 has aleft-hand twist. The current in conductor 121 generates the magneticfield described by vector 124; vector 125 applies to conductor 122 andvector 126 applies to conductor 123. Vectors 125 and 126 combine toproduce the combined vector 127. For reasons of symmetry, this vector127 is at a right angle to the axis of the cable and so shares the sameorientation as vector 124. As a result of the phase opposition, thismeans the two magnetic fields compensate each other no matter what thedirection is, except for the difference in the magnitudes.

FIG. 15 shows an arrangement with a PE or ground conductor 131 and twosplit conductors 132, 133 and 134, 135. Conductors 132, 135 in the outercross-sectional circle have a right-hand twist and the conductors in theinner cross-sectional circle 137 have left-hand twist. The opposingdirection of twist of both current-carrying conductors 132 and 133, 134and 135 means that the values and directional orientations of themagnetic fields equalize one another more effectively. FIG. 16 shows acorresponding arrangement for three-phase current (delta operation). Inthe center, this incorporates a protective earth (PE) 141 and conductorsfor each phase 1411,1412; 1421,1422; 1431,1432 which are split into twosingle conductors and are distributed in symmetrical circles evenlyaround an inner circle (defined by 1412, 1421, 1432) and an outer circle(defined by 1411, 1431, 1422). The single conductors of the inner circle144 all have a left-hand twist and those of the outer circle 145 allhave a right-hand twist.

FIG. 17 shows an arrangement of conductors in a cable which specificallyfulfills exacting requirements regarding magnetic field compensation andis suitable for three-phase current transmission with a neutralconductor (star connection) and a centrally arranged ground conductor14PE. The three phase conductors 151,152,153 are each divided into foursingle conductors 1511 to 1514; 1521 to 1524; 1531 to 1534. They aredistributed in equal proportions around the cross-section of an outercircle 155, and in the example shown, have a right-hand twist(1511,1512; 1521,1522; 1531,1532) or alternatively, they are have anopposing twist (left-hand twist) and are distributed evenly around aninner circle 154 (1513,1514; 1523,1524; 1533,1534). Given asymmetricalthree-phase current operation, the neutral conductor 15N also carriescurrent, therefore this conductor also has to be included in thedistribution system. This means that the single conductors 15N1, 15N2have to be evenly distributed around the outer circle 155, and thesingle conductors 15N3 and 15N4 have to be evenly distributed around theinner circle 154. In order to shield the electrical field, theprotective earth can be incorporated in the form of single conductorssplit as often as required and arranged outside the outer conductorwhich has a right-hand twist or additional shielding can be provided forthis task using familiar methods.

FIG. 18 shows an electrical line system arranged in accordance with thepresent invention in the form of a twin lead, for a two-phase systemwith conductor 161 and the conductor which is split into two parts 162,163 which are arranged symmetrically around the conductor 161. Ifnecessary, a protective earth 16PE1 is arranged around the outside,which can be supplemented by a second, symmetrically arranged protectiveearth 16PE2 in order to improve the shielding of the electrical field.

Twin leads are generally located in the surface zone of plastering onwalls. This means the main threat from radiation is from that side ofthe wall in which the twin lead is located in the plaster, because it isnot possible to approach the lead from the other side of the wall by adistance less than the thickness of the wall. Investigations haverevealed that the radiation diagram for a twin lead as shown in FIG. 18in the plane of the diagram is such that a minimum radiation level isensured perpendicular to the plane of the conductor, related toconductor 161, and that in directions at an angle of 45° to thisconductor, the magnetic field is indeed compensated, but to a notablyinferior degree. However, if the positions of single conductors 162 and163 are moved somewhat outside the plane of the twin lead conductor andif the twin lead is moved to a different position in the wall so thatthe single conductors are moved to a position where they are less deeplyrecessed into the wall than the conductor 161, it can be seen that thetotal magnetic field of the twin lead on the plastered side of the wallis considerably reduced, and that the previous adjacent 45° maximumvalues practically disappear. An analysis of the vectors involved showedthat if the distance between conductors 161 and 162 or 161 and 163 isapproximately 10 mm each and a height offset of approximately 10% of thedistance between the conductors is introduced, that is to sayapproximately 1 mm, these measures have the effect described above, andthis effect applies at a distance of approximately 100 mm from the twinlead.

FIG. 19 shows an electrical line system in the form of a twin lead for athree-phase current system. Two other conductors are split into twoparts 172, 173 and 174, 175 and are arranged around the phase conductor171. It can be expected that even the neutral conductor will carrycertain currents, and so this conductor is also split into two parts176, 177 and arranged symmetrically. An additional conductor 178 servesas the protective earth. The eight individual conductors can also berealized using two twin leads arranged adjacent to one another. FIG. 20shows the same system as FIG. 19, with the system realized using twotwin lead planes arranged in a stack in this case. In this illustration,both the other individual phase conductors are located as closely aspossible to each phase single conductor in order to achieve optimummagnetic field compensation, conductor 1821 with conductors 1812 and1832, conductor 1811 with conductors 1822 and 1831, conductor 1812 withconductors 1821 and 1832, conductor 1832 with conductors 1821 and 1812,conductor 1822 with conductors 1811 and 1832, conductor 1831 withconductors 1811 and 1822. In order to reduce the electrical fieldradiation, the neutral conductor 184 and the PE or protective earthconductor 185 are located on the room side.

FIG. 21 shows an even denser concentration of the three phase conductorsin relation to the cross section of the cable. The PE (protective earth)194 and the neutral conductor 195 are located at the side in the doublelayer arrangement of the twin leads.

It is sensible for the twin leads shown positioned in a stack in thefigures mentioned above to be combined into a single cable by enclosingthem in one covering. In the case of standard twin leads, this unifiedcovering can take the form of an outer sheathing made of standardflexible material.

As far as insulation for these cables is concerned, the forms to berecommended are those such as explained, for example, in the book"Haustechnik" by Holger/Laasch, published by B. G. Teubner, Stuttgart1989, on pages 353 and 354, for example types NYIF, NYM and NYY.Concerning the extension cables which have been mentioned, theconstruction must have the standard degree of flexibility, especially inthe case of the single conductors.

FIG. 22 shows, for example, the results which can be obtained using aline system constructed in accordance with FIG. 3. This is therefore asingle phase system. The measurement on the abscissa axis is thedistance from the outermost conductor in meters. The ordinate axisrecords the magnetic flux density of the magnetic field in micro telsadepending on the value given at the corresponding distance value.

Curve 201 shows the condition without compensation for the same currentvalue. The remaining curves show the sequence for the followingconditions:

2021 the compensation point PK upon which the calculation is based ispositioned at a distance of approximately 18 meters from the solder ofthe outermost conductor on the surface of the earth (ordinate),

2022 as above, at a distance of approximately 24 meters,

2023 as above, at a distance of approximately 30 meters,

with the PK at a corresponding height to the height of the center of theline system which is connected to earth in each particular case. Theclear reduction effect is apparent. The telsa values given arecalculated from the current presumed to be flowing in the system and thesystem geometry.

FIG. 23 shows a possible method of reducing the AIB in the vicinity ofrailway systems by the traction current of electric locomotives of thetype used by the Deutsche Bundesbahn (German Federal Railways).

In this case, the single phase current flows in the overhead contactline 21L1 and flows back as a return current along rails 21S1 and 21S2.This arrangement has the vertical axis of symmetry 21S10.

The magnetic field is minimized at compensated point 21PK which islocated at the distance 21rk from the axis of symmetry 21S10 of the railsystem. As far as the height is concerned, the compensation point 21PKis fixed by the horizontal axis of symmetry 21S11. This point is at adistance 21d1 from the rails 21S1 and 21S2, and is at the same distance21d2 from the overhead contact line 21L1.

A single-phase current in the outward and return conductors (21L21,21L22) compensates the magnetic field at point 21PK. The outward andreturn conductors 21L2, 21L22 are located symmetrically to the axis 21A2at a distance of 21d1 or 21d3 from the compensation point 21PK.

Due to the current in conductors 21L1, 21L2 and due to the distance ofthese conductors from the compensation point 21PK, a magnetic field isgenerated at the compensation point PK whose characteristics are definedby vectors 211 and 212 in FIG. 23. The currents in conductors 21L1 and21L2 are opposite in sign above and below the axis of symmetry 21S11.Accordingly, a mirror-image magnetic field is generated at compensationpoint 21PK by the compensation current in conductors 21L21, 21L22 and21L1. The partial components 214 and 215 (assuming equal values for thetraction current and the compensation current) add up to the value 216.This means vector 219 can be created simply by finding the necessarygeometrical arrangement and compensating current value. The value ofvector 219 will then correspond to the value of vector 213, and willshare the same axis of directional orientation. The vectors compensateone another fully because they lie at an angle of 180° to each other(phase opposition). The pre-requisite for continuous total compensationof the magnetic field is that the temporal sequence of the currents inboth systems should be identical. It is advantageous if only thestrength of the current in conductors 21L21 and 21L22 is important asthe outward and return current for magnetic field compensation. In thiscase, the circuit can be operated with the minimum current required forgenerating the current necessary for compensation. This means thecompensation current system uses a practically negligible amount ofelectrical power.

In contrast to the application shown in FIG. 23, the second singleconductor of the compensation line system which carries the current+22Ik can be located in the ground. This arrangement is shown in FIG.24. This figure also shows the single conductor 21L22 with current -22IKwhich provides even more straightforward compensation. This singleconductor can however be discarded, and in this case the vector patternis altered accordingly. This method offers the advantage that thestandard railway line layout is not different from the previous one. Thearrangement shown in FIG. 24 has the single conductor located in theground, current +22IK and the single conductor 21L22 with current -22IK,and offers the significant advantage that there are no spatialrestrictions on the area within which effective single conductors can belocated.

If one is prepared to accept specific locational restrictions regardingthe position of the single conductor in the ground in order to providean effective solution in accordance with the present invention, theadditional single conductor 21L22 can be discarded. In this case, thecompensation current -22IK which would have been carried in thisconductor should be passed through the track 21L21.

In FIG. 25, the time-dependent course of the current or the course ofthe magnetic field resulting from the current is to be taken intoconsideration in addition to the time-dependent occupancy of sections ofa current supply section, for instance between a separation point 2511for current feed and an overhead contact line separation point 2541. Inpractice, compensation cannot be achieved exactly up to the point wherethe moving train is currently located. If the distances between theoverhead contact line separation points are large, this would mean thatat times a section of the overall system would not be in a compensatedcondition and would be radiating, which is not desirable. In a furtherdevelopment of the present invention, this difficulty can be counteredby for example not assigning a compensation section of the same lengthto the individual current supply sections 2511 to 2541, and insteadsubdividing the compensation section into several considerably smallersections 2517, 2527 and 2537 each of which has, for example, the samelength. Sensor devices 2523 and 2533 are fitted next to the tracks atthe transition points 2521, 2531 of the individual subsections which liebetween the termini 2511 and 2541, whereby the sensor devices 2523 and2533 emit an electrical signal by means of an outgoing coil when currentflows in the track and the electrical signal is used to confirm one ofthe items of switching equipment 2522 or 2533 which are each assigned toone of the sensors. These items of switching equipment each only providecompensation current to those subsections in which operating current forthe train is flowing in the railway traction current circuit. For thisfunction to be effected, it is advisable for the individual items ofswitching equipment to contain one normally open contact pair and onenormally closed contact pair. The circuit details can be seen in FIG.25. The relay contacts are illustrated in the rest position. In thiscircuit, the compensation cable system is supplied with the requiredcompensation current 25IK section by section from transformer 25T1 as afunction of the traction current 25IB flowing in each section at thetime. The transformer 25T2 supplies the adjacent current supply section,starting with 2511. Both the current supply sections from 2518 and 2508are electrically separated at point 2511. When the locomotive crossesthe supply section separation point 2541 traveling in the direction2538→2548, no more current flows between 2511 and 2541. All directconnections in the compensation line system are reestablished in theitems of switching equipment 2522 or 2532. If the locomotive istraveling in the opposite direction 2548→2538, the traction current 25IBinfluences all sensor devices 2523 or 2533 through their transducercoils and the entire section is supplied with compensation current.After the sensor devices 2533 or 2523 have been passed, the appropriatenormally open and normally closed contact pairs ensure that theirassigned subsections are cleared of compensation current.

The arrangements described below are concerned with further advantageousdetails regarding connection equipment for cables and lines referred toas extension cables, such as those used for electrical devices in thehome.

FIG. 26 reproduces the connection of an extension cable to a standardsafety plug 260. In place of the previous standard cable with threeconductors, a cable 264 with five conductors is used, which is connectedto the screw-type terminal of the plug in such a manner that the groundconductor 2611 is connected to the screw-type terminal 2614 provided forit and, of the other four remaining conductors (two of which form theneutral or zero conductor and two the phase conductor), the singleconductors of the neutral conductor 2621, 2622 are connected to thescrew-type terminal of one of the connector pins 2624 and the singleconductors 2631, 2632 of the phase conductor are connected to thescrew-type terminal of the other connector pin 2634. Both the singleconductors of the neutral conductor and both the single conductors ofthe phase conductor each have the same marking to guarantee correctconnection allocation to both cable ends (double dot marking 2633 forthe phase conductor 2634 and single dot marking 2623 for the neutralconductor 2624).

When using low-radiation electrical conductors such as those used asextension cables or as device connection leads, it is particularlyadvisable from the point of view of providing shielding against theelectrical field to design the plug connections so as to providereliable protection against switching over the connection contacts.

This purpose is served by a small lug 265 which lines up with acorresponding indentation in the mating part of the plug connection, inother words in the safety socket or in the safety in-series adapter. Asillustrated, the lug can have a square block shape or be a bluntpyramid, or else be pin-shaped or in the form of a frustum of a cone.

Due to the large number of conductors which have to be specified in thescrew-type terminal equipment in accordance with FIG. 26, a shape whichis different from the version used as standard is to be recommended.

FIG. 27 shows a favorable terminal device arrangement for plugs,sockets, in-series adapters or device connections. Several types ofarrangements are presented together in this figure.

The standard arrangement 271 incorporates a terminal section 2711 withthe terminal screw 2712 which passes into the contact pin 2713. A borein 2711 is provided for accommodating the conductor or wire.

For the purpose of the present invention, a bore is provided with alarger diameter as shown by the terminal section 272 with the terminalscrew 2722, contact pin 2723 and bore 2721. In the standard arrangement,the diameter of the bore is approximately 2 mm. For the purpose of thepresent invention, this diameter should be at least approximately 4 mmin order to ensure that the wire can be introduced easily.

Another possibility is to design the terminal section in the form of aslotted hole 2731 as shown on the terminal section 273. Number 2732 isthe terminal screw and 2733 is the contact pin.

Given a large number of single conductors, it is to be recommended thatthe terminal section 274 should consist of two terminal sections 273which are held together by means of a screw connection 2743. The twoterminal sections are numbered 2741 and 2742.

These types of arrangements are especially interesting for cables andcable connections in accordance with FIGS. 11, 12 and 13.

As already mentioned, cases may arise in which it is desirable toprovide a safety mechanism to prevent the connection contacts from beingswapped over out of their correct positions when the mating part isplugged in, for example to maintain the electrical shielding alreadymentioned. In the device shown in FIG. 26, it is necessary to design theplug and its mating part specifically to achieve this. This difficultycan be countered by providing at least one push-on disk for the plug,and in a preferable embodiment, a corresponding push-in disk for themating part, for example the safety socket.

The push-in disk 281 incorporates the standard notches for safetyconnections. These are indicated by number 2813. However, the holes 2811and 2812 for the contact pins have small lug-shaped projections 2814which protrude into the cross-section of the hole. A groove-shapedchannel corresponding to each lug-shaped projection is incorporated intoeach individual contact pin of the plug (not shown in FIG. 28). Thismeans the plug can also be used in standard safety sockets and in-seriesconnections, and standard safety sockets and in-series connections canalso be used for the purposes of the present invention.

If the operator does not wish the shape of the contact pins to bedifferent from the standard form, an arrangement along the lines ofnumbers 282 or 283 shown in FIG. 28 is to be recommended. In 282, thepush-in disk incorporates an indentation 2824 for accommodating a pincorrespondingly arranged in the plug, similar to the lug 265 in FIG. 26.The indentation is located in an off-center position outside the planeof a theoretical line 2835 whose course is determined by the contactpins. Numbers 2821 and 2822 are the openings for introducing the contactpins. Number 2823 refers to the familiar notches in safety connections.In number 283 the indentation 2834 is indeed located on the plane ofline 2835, but is in an asymmetrical position. In 283, number 2833denotes the standard safety connection notches and numbers 2831 and 2832refer to the openings for insertion of the contact pins.

FIG. 29 shows another push-in disk 2911 and a corresponding push-on disk2921 appropriate for an arrangement in accordance with FIG. 26. The lugmarked 2917 is the same type as 265 and the corresponding accommodationmechanism or indentation in the push-in disk 2911 is numbered 2926. Inaddition, an engagement profile of a similar type projecting in theopposite direction is provided. This consists of a lug 2927 in thepush-in disk 2921 and a corresponding indentation 2916 in the push-ondisk 2911. The position of the individual parts when plugged togethercan be seen from the two cross-sectional views 293 and 294 of theconnection. This arrangement offers the additional advantage that if thetwo connection elements are pushed together incorrectly, the lugs lineup with each other, thus making it very difficult if not impossible toform a connection.

Push-in disks are themselves used in safety sockets of prior art, wherethey are referred to a child-proof inserts. As is known, these insertscover the openings into which the contact pins are inserted when thesocket is in use. In a further embodiment of the present invention, thepush-in disks serve, in contrast to this mechanism, the purpose ofunambiguous allocation of the neutral conductor pin of a plug to theneutral conductor bushing in the socket or in the mating in-seriesadapter component. As in the case of the inserts of prior art, thesepush-in disks can be held in place by a clamping mechanism. In the caseof a plug, the push-on disk is designed as a mating part and simplypushed on, where it is held on either by means of the standard centralscrew or else by being stuck on with glue. Furthermore it isadvantageous if a socket or mating part of an in-series adapter which isprovided with a push-in disk in accordance with a further embodiment ofthe present invention can also be used for the familiar two pin Europlug (plain connector). To this end, a push-on disk of an appropriatedesign can be allocated to this plug.

The method of examination applied in order to explain the presentinvention is based on the assumption that the entire system is to beviewed as a quasi-static system, because the conductor clearances andalso the distance between the compensation zone and the line system areso small in relation to the wavelength determined by the operatingfrequency of the line system, that it is possible to assign thecompensation zone to the narrowest proximity.

If one considers the distribution of the magnetic field in across-sectional plane through the line system, it becomes apparent thatthe magnetic field in the plane of the cross-section demonstratesmaximum and minimum zones whose angular position and distance related tothe line system are dependent on the geometrical position of theindividual conductors and on the currents flowing within theseconductors.

In the sample arrangements presented, the arrangement of the singleconductors is purposely such that they are located in a stack--relatedto the compensation zone. In a further embodiment of the presentinvention, it is however also possible to arrange the single conductorsin a cascade--related to the compensation zone. In accordance with thisfurther embodiment, it is also possible to locate the single conductorsboth in a stack and in a cascade. These cases are explained in moredetail with the assistance of the sample arrangements shown in FIGS. 30to 34. In the final analysis, this amounts to a broader application ofthe split conductor principle explained above.

FIG. 30 shows a single phase line system with one outward and one returnconductor. The outward current flows in the outward conductor 303whereas the return current, split into two equal parts, flows in thereturn conductor which is split into the single conductors 301 and 302.The cross-sectional plane of the line system (which is presumed to liein a straight line) formed by the individual conductors is shown in theplane of the drawing. In a symmetrical arrangement of conductors, allthree conductors are located along an axis 30A, and the clearances 30d1and 30d2 between the conductors are equal. At a certain distance 30ralong the axis 30A from conductor 303 which is located in the center,the magnetic field generated by the currents flowing in the conductorsis shown to alter with distance and be inversely proportional todistance 30r. If one observes the magnetic field at a point 30KP locatedon the common axis 30A of the three conductors, the size of the magneticfield 303H to be allocated to conductor 303 is determined by thedistance 30r. Magnetic fields 301H and 302H at point 30KP are generatedby the currents flowing in the opposite direction in both conductors 301and 302 and have the same direction of orientation as the magnetic field303H which is generated by the current flowing in conductor 303 but withopposite signs (phase opposition). Additionally, in the example only onecurrent each is flowing in conductors 301 and 302 and this is half aslarge as the current in conductor 303. The following situation appliesin respect to the distance: 301H is a function of 1/(30r-30d1) and 302His a function of 1/(30r+30d2). Therefore, the magnetic field 301H isslightly larger than half the value of 303H and the magnetic field 302His slightly smaller than half the value of 303H.

Although the currents generated in the conductor 301 and 302 are of thesame amount at the start, in other words half as large as the current inconductor 303, the sum of the magnetic fields 301H and 302H at point30KP is therefore not identical to the size of magnetic field 301H whichis generated by the current flowing in conductor 303. As can be shownfor example by means of a series expansion, the currents in both theexternally located conductors always generate a slightly greater totalmagnetic field at point 30KP than that field generated by the currentflowing in conductor 303; in other words,(301H+302H)≈303H(1+(30d/30r²)), if the arrangement of conductors issymmetrical, i.e. if the distances 30d1 and 30d2 from the centralconductor are identical (30d1=30d2=30d).

Zero balancing of the magnetic field can however be effected if thedistance of the conductor 301 and/or the distance of conductor 302 frompoint 30KP is increased until the total magnetic field to be allocatedto these two conductors is reduced to such a size that it corresponds tothe magnetic field generated by the current flowing in 303. Thisasymmetrical arrangement of conductors has the corollary that themagnetic field compensation on the side of the line system which isfacing away from point 30KP (30r<0) is slightly reduced.

In accordance with the directives arising from the present invention,the following observations consequently arise in connection with the useof split conductors (single conductors) in a line system:

In a line system originally with n current-carrying paths, when theconductors are routed in parallel with the route of the cable, at least2n-1 conductors are required in order to produce an arrangement inaccordance with the present invention, for example in the case of asingle phase system this is three conductors and five conductors for athree-phase system. If the conductors do not run in parallel to the axisof the cable, as for example if the conductors are twisted in a powercable, it is advantageous if all conductors are split at least once.This procedure therefore requires at least four conductors, taking theexample of a single phase system, and at least six conductors for athree-phase system.

FIGS. 31 to 33 show fundamental possibilities for conductor arrangementswhich adopt this principle to achieve zero field compensation at point30KP.

FIG. 31 shows a single phase system with conductors 3011 to 3023. FIGS.32 and 33 show a three-phase system with conductors 3031 to 3055.

To enable easier comprehension, FIGS. 31 and 32 also show thecorresponding single conductor distributions for the arrangement withconductors in a stack as described previously. In this case, the splitconductors 3011, 3012 and 3031 to 3034 and 3051,3052 are arranged withsymmetrical axis angles in order to achieve magnetic field compensationin the individual single conductors which carry equal partial currents.Arrangements which have asymmetrical axis angles require differentdistances between the single conductors and the compensation pointand/or different current distributions amongst the single conductors. Incontrast, the single conductors 3021, 3022 and 3041 to 3044 and 3053,3054 are all on the same axis. In both cases, therefore, the directionsof the field vectors which are to be assigned to all original (i.e.unsplit) conductors possess the same orientation, as is required forcomplete magnetic field compensation.

In order to achieve zero field compensation, it is therefore onlynecessary to adjust the vector values so that the sum of the vectoramplitudes, with due consideration for the orientation and signs of thevectors, is at least approximately zero. This can be arranged byselecting the distance between the split conductor and the compensationpoint 30KP and/or, in the case of the magnetic field, by distributingthe current accordingly in the current path between the (split) singleconductors which make up the current path.

FIG. 33 shows a combination of both of these types of compensationarrangements for conductors 3051 to 3055 in a three-phase system. Bothmatching (split) single conductors 3051 and 3052 are arrangedsymmetrically in relation to their axis angles to the compensation point30KP5 whereas the two (split) single conductors 3053, 3054 lie on acommon axis to the unsplit conductor 3055 and the compensation point30KP5. As a consequence, all combined vectors have the same orientationin relation to axis 30A5 provided that the current is distributedaccordingly.

Both these types of compensation open up another advantageouspossibility, namely to achieve simultaneous compensation in severalareas of space at once. If one looks at FIG. 30, it is apparent that asituation corresponding to that described using FIG. 3 results for theremote axis 30V at a right angle to the remote axis 30A defined byconductors 301, 302, 303.

As a further development of the present invention, if for example, theunsplit conductor 303 is positioned slightly further back in anarrangement in accordance with FIG. 30, whereby this conductor 303 ispositioned in the region 30v<0, a further compensation zone is createdaround 30PV if the currents in the individual conductors are distributedaccordingly. The result is an arrangement similar to that described indetail using FIG. 3. It is true that the zero compensation of themagnetic field in the 30r direction is slightly reduced, but this effectis nevertheless of only of a secondary order, and can thereforegenerally be neglected. The zero value for 30v and also for 30r is atthe intersection of axes 30V and 30A. Consequently, negative values of30v and 30r are located on the opposite side of the zero point in eachcase.

This finally produces an arrangement of conductors as shown in FIG. 34,where it is possible to achieve practically total zero compensation ofthe magnetic field at point 31PV and point 31PR by means of appropriatepositioning of the conductors 311,312,313. The dimensions entered in thedrawing are only valid for a specific current value which was taken asthe basis for calculations, and represent distances in meters. Withassistance from a suitable computer program, the two compensation points31PV and 31PR of the magnetic field can be located wherever desirableover the surface area of the cross-sectional plane, and the magneticfield values can be minimized. In this way, the positions of the threeconductors 311, 312, 313 can be determined for a specific application sothat the magnetic field compensation achieved is optimally suited to therequirements. The sample arrangement shown in FIG. 34, for ahigh-voltage line with single phase operation, can be profitably used incases where the first compensation point 31PV is located atapproximately the height of a body standing directly beneath ahigh-voltage line, and where a second compensation point 31PR should belocated laterally to the first, for example in the center of a houselocated on one side of the high-voltage line. Such cases occur inpractice if, for example, a path runs under a high-voltage line which isused to supply a railway traction current circuit which passes through aresidential area.

The present invention is, of course, in no way restricted to thespecific disclosure of the specification and drawings, but alsoencompasses any modifications within the scope of the appended claims.

What I claim is:
 1. An electrical line system comprising:at least onemagnetically compensated line system unit comprising at least two mainconductors for transmitting electrical energy and further comprising atleast one auxiliary conductor extending parallel to said at least twomain conductors; said at least two main conductors and said at least oneauxiliary conductor being phase-synchronized when said at least oneauxiliary conductor carries current during operation of said electricalline system; wherein said at least two main conductors and said at leastone auxiliary conductor are arranged in a spatial arrangement relativeto a first reference point in a first space extending parallel to saidelectrical line system, and wherein the currents flowing in said atleast two main conductors and said at least one auxiliary conductor areselected such that a vector sum of the magnetic field componentsemanating from said at least two main conductors and said at least oneauxiliary conductor is substantially equal to zero at said firstreference point; and wherein said spatial arrangement is defined by adistance between said at least two main conductors and said at least oneauxiliary conductor relative to said first reference point and by aspatial distribution of said at least two main conductors and said atleast one auxiliary conductor relative to said first reference point. 2.An electrical line system according to claim 1, wherein:at least one ofsaid two main conductors is a split conductor that is split into atleast two single conductors and at least one of the remaining mainconductors is an unsplit conductor; one of said single conductorsfunctions as said at least one auxiliary conductor; and said spatialarrangement of said at least two single conductors is determined as afunction of the currents flowing in said unsplit conductor and said atleast two single conductors such that the magnetic field of said unsplitconductor is at least approximately compensated by the magnetic field ofsaid single conductors in said first space extending parallel to saidelectrical line system.
 3. An electrical line system according to claim2, wherein the currents in said single conductors are in phase andwherein said single conductors are positioned on opposite sides of aplane defined by a longitudinal extension of said at least one unsplitmain conductor and said first reference point.
 4. An electrical linesystem according to claim 3, wherein ends of said single conductors areshort-circuited to one another.
 5. An electrical line system accordingto claim 3, wherein said single conductors have substantially identicalelectrical resistance and are positioned mirror-symmetrical to saidplane.
 6. An electrical line system according to claim 2, wherein thecurrents in said single conductors are in phase opposition and whereinsaid single conductors are positioned on a same side of a plane definedby a longitudinal extension of said at least one unsplit main conductorand said first reference point.
 7. An electrical line system accordingto claim 6, further comprising an electrical power supply connectedbetween said single conductors, wherein the current of said power supplyis phase-synchronized with the current transmitted with said electricalline system.
 8. An electrical line system according to claim 1, furthercomprising at least one magnetically non-compensated line system unit,wherein said at least one magnetically compensated line system unit andsaid at least one magnetically non-compensated line system unit extendsubstantially parallel to one another, wherein the magnetic fields ofsaid at least one magnetically compensated line system unit and at leastone magnetically non-compensated line system unit act on said firstspace extending parallel to said electrical line system, and whereinsaid at least one magnetically compensated line system unit has aspatial arrangement such that at least partially a compensation of themagnetic fields of said magnetically non-compensated line system unit isachieved.
 9. An electrical line system according to claim 1, whereinsaid at least two main conductors for transmitting electrical energy andsaid at least one auxiliary conductor are arranged in a stackedarrangement relative to a plane defined by a center line of said firstspace and a center line of said electrical line system.
 10. Anelectrical line system according to claim 1, wherein said at least twomain conductors for transmitting electrical energy and said at least oneauxiliary conductor are arranged adjacent to one another in a planedefined by a center line of said first space and a center line of saidelectrical line system.
 11. An electrical line system according to claim1, wherein said at least two main conductors and said at least oneauxiliary conductor are arranged in a spatial arrangement relative tosaid first reference point in said first space extending parallel tosaid electrical line system and relative to a second reference point ina second space parallel to said electrical line system and wherein thecurrents flowing in said at least two main conductors and said at leastone auxiliary conductor are selected such that a vector sum of themagnetic field components emanating from said at least two mainconductors and said at least one auxiliary conductor is substantiallyequal to zero at said first and second references points.
 12. Anelectrical line system according to claim 2, wherein said singleconductors are arranged about said unsplit conductor so as to besubstantially positioned on a circle.
 13. An electrical line systemaccording to claim 2, wherein said at least one magnetically compensatedline system unit is a cable with insulation cover.
 14. An electricalline system according to claim 13, wherein said cable carriessingle-phase current and comprises one of said split conductors and oneof said unsplit conductors, wherein said single conductors and saidunsplit conductor are each individually insulated and wherein saidsingle conductors symmetrically surround said unsplit conductor.
 15. Anelectrical line system according to claim 14, further comprising aneutral conductor, wherein said single conductors are arranged aboutsaid neutral conductor so as to be substantially positioned on a circle.16. An electrical line system according to claim 14, further comprisinga neutral conductor split into single neutral conductors, wherein saidsingle neutral conductors surround said single conductors of said mainconductors so as to be substantially positioned on a circle in order toshield against the formation of an external electrical field.
 17. Anelectrical line system according to claim 16, further comprising aground conductor arranged centrally with respect to said singleconductors of said main conductors and said single neutral conductors.18. An electrical line system according to claim 14, further comprisinga ground conductor split into single ground conductors, wherein saidsingle ground conductors surround said single conductors of said mainconductors in order to shield against the formation of an externalelectrical field.
 19. An electrical line system according to claim 13,wherein said cable carries polyphase current and comprises one of saidsplit conductors for each phase of said polyphase current, wherein eachone of said single conductors is insulated, and wherein all of saidsingle conductors are substantially positioned on a circle.
 20. Anelectrical line system according to claim 19, further comprising aneutral conductor, wherein said single conductors are arranged aboutsaid neutral conductor so as to be substantially positioned on a circle.21. An electrical line system according to claim 19, further comprisinga neutral conductor split into single neutral conductors, wherein saidsingle neutral conductors surround said single conductors so as to besubstantially positioned on a circle in order to shield against theformation of an external electrical field.
 22. An electrical line systemaccording to claim 21, further comprising a ground conductor arrangedcentrally with respect to said single conductors and said single neutralconductors.
 23. An electrical line system according to claim 18, furthercomprising a ground conductor split into single ground conductors,wherein said single ground conductors surround said single conductors inorder to shield against the formation of an external electrical field.24. An electrical line system according to claim 13, wherein said cablehas free ends, each one of said free ends comprising a connection devicein the form of a plug, and wherein an electrical connection of saidsingle conductors of each one of said split conductors is provided ineach one of said connection devices.
 25. An electrical line systemaccording to claim 24, wherein said electrical line system furthercomprises a counter member for each one of said connection devices andwherein said counter members and said connection devices are embodiedsuch that said connection device can be inserted into said countermember only in one position in which a neutral conductor of saidconnection device contacts a neutral conductor of said counter member.26. An electrical line system according to claim 13, wherein said cableis configured as a twin lead and wherein said single conductors areslightly offset relative to a plane defined by said twin lead in whichplane said unsplit conductor is positioned.
 27. An electrical linesystem according to claim 26, wherein said cable carries polyphasecurrent and wherein said single conductors are arranged in two planesthat are essentially parallel to one another.
 28. An electrical linesystem according to claim 2, wherein said at least one magneticallycompensated line system unit is a buried cable unit for transmittinghigh voltage current and wherein said single conductors are in the formof separated conductors.
 29. An electrical line system according toclaim 2, wherein said single conductor has a cross-sectional area thatis smaller than a cross-sectional area of said unsplit conductor.
 30. Anelectrical line system according to claim 29, wherein a sum of saidcross-sectional areas of said single conductors is substantiallyidentical to said cross-sectional area of said unsplit conductor.
 31. Anelectrical line system according to claim 2, wherein said singleconductors of each one of said split conductors have the sameidentification markings.
 32. An electrical line system according toclaim 31, wherein said identification marking is a color code.
 33. Anelectrical line system comprising:at least one magnetically compensatedline system unit comprising at least two main conductors fortransmitting electrical energy and further comprising at least oneauxiliary conductor extending parallel to said at least two mainconductors; said at least two main conductors and said at least oneauxiliary conductor being phase-synchronized when said at least oneauxiliary conductor carries current during operation of said electricalline system; wherein said at least two main conductors and said at leastone auxiliary conductor are arranged in a spatial arrangement relativeto a first reference point in a first space extending parallel to saidelectrical line system, and wherein the currents flowing in said atleast two main conductors and said at least one auxiliary conductor areselected such that a vector sum of the magnetic field componentsemanating from said at least two main conductors and said at least oneauxiliary conductor is substantially equal to zero at said firstreference point; and wherein said spatial arrangement is defined by adistance between said at least two main conductors and said at least oneauxiliary conductor relative to said first reference point and by aspatial distribution of said at least two main conductors and said atleast one auxiliary conductor relative to said first reference point;wherein at least one of said two main conductors is a split conductorthat is split into at least two single conductors and at least one ofthe remaining main conductors is an unsplit conductor; wherein one ofsaid single conductors functions as said at least one auxiliaryconductor; wherein said spatial arrangement of said at least two singleconductors is determined as a function of the currents flowing in saidunsplit conductor and said at least two single conductors such that themagnetic field of said unsplit conductor is at least approximatelycompensated by the magnetic field of said single conductors in saidfirst space extending parallel to said electrical line system; whereinsaid at least one magnetically compensated line system unit is a railwaytraction current system having a railway traction current line wherein afirst one of said main conductors is an overhead contact line or alateral contact line and wherein a second one of said main conductors isin the form of a track, wherein one of said first and second mainconductors functions as said split conductor, and wherein said splitconductor is formed by providing a separate conductor in addition to therespective main conductors.
 34. An electrical line system according toclaim 33, wherein said track functions as said split conductor and iscomprised of two of said single conductors, with a first one of saidsingle conductors being the railway track proper and with a second oneof said single conductors being a separate conductor, wherein saidseparate conductor is arranged such as a function of the current flowingtherethrough that a compensation of the magnetic field components takesplace in said first space.
 35. An electrical line system according toclaim 33, wherein said separate conductor extends underground andparallel to said track.
 36. An electrical line system according to claim33, further comprising a transformer for supplying a compensationcurrent and wherein said single conductors of said split conductor eachhave a first and a second end and are connected to one another with saidfirst ends, wherein said transformer is connected to said second ends.37. An electrical line system according to claim 33, further comprisinga plurality of transformers for supplying a compensation current,wherein each one of said transformers is connected between ends of twoof said single conductors of said split conductor.
 38. An electricalline system according to claim 33, wherein said separate conductor isdivided into short conductor sections, said electrical line systemfurther comprising:a sensor device, wherein said sensor devicedetermines in which one of said short conductor sections current isflowing; and switching elements positioned between neighboring ones ofsaid short conductor sections, wherein said switching elements supplycompensation current only to those ones of said short conductor sectionscorresponding to portions of said first and second main conductorscarrying current.
 39. An electrical line system according to claim 38,wherein said sensor device is a magnetic field sensor.
 40. An electricalline system according to claim 33, wherein a plurality of said separateconductors are provided substantially in parallel to said railwaytraction current line.